Gamma-ray bursts are the most violent explosions in the universe. In a fraction of a second, they can release more energy than the sun will emit across its entire 10-billion-year lifetime. Most are over before you've had time to register them, gone in seconds, minutes at most. So when something arrived on 2 July 2025 that kept going for seven hours, fired three distinct bursts spread across an entire day, and then left behind an afterglow lasting months, astronomers knew immediately they were looking at something completely new.